There are tons of sitebuilders out there — think Wix or Wordpress — that excel at displaying content. But when you want functionality, like a slideshow or a shopping cart, POWr Plugins provides a solution with 53 plugins and counting. In my time at POWr, I created a variety of plugins like Weather and Social Feed in addition to building core infrastructure like the login system.
Most of POWr's backend is written in Ruby on Rails, but I also wrote a secondary server in Node.js for long running requests. The frontend relied on jQuery for interactivity and templating with Underscore.js. It was hosted on Heroku with static assets served from AWS S3 and cached with Cloudfront.